Steam turbine



Feb; 22,1927.`

`F. LOSEL STEAM TURBINE Filed AusLlG. 1924 Patented Feb. 22, 1927.

unirse STATES FRANZ Lser., or nanna, CZECHOSLOVAKIA.

,STEAM TURBINE.

Application led August' 16, 1924, Serial No. 732,414, and in Austria Iune 5, 1924;.

This invention relates to multi-stage elas-v tic fluid turbines, particularly turbines for utilizing high pressures.

The object of the invention generali isY a turbine of this character which is. capa le of more eicient regulation andeconomical 'operation than prior turbines. l

The efficiency of a steam turbine falls off at partial loads whether throttle or the more ecient nozzle regulation is used, and the object of my invention is a turbine whose regulation may be satisfactorily eected with substantial reduction in the losses usually incident to regulation for small or i high pressure turbines of lar e capacity, and

below normal loads. My invention resides generally in constructing a turbine for full admission or` full Steam supply at one 0r more denite partial load lvalues as well asA also to turbines of the low fluid velocity type. More specifically the high pressure end o the turbine is constructed to operate with full steam supply full steam pressure at all times, but the nozzles in the high pressure end arel only -capable of admitting and receiving a suiiicient quantit of steam'to operate the turbine at a de nite partial load value, while for full load or larger loads the turbine is constructed and adapted to receive live steam at full steam supply at one or more intermediate'stage groups, each successive group ofthe latter being adapted to admit only the additional steam required l for a particular load value. By the successive full admissions to the groups of nozzles the main variations in regulation may be effected, such for example as one-half load for the first group of nozzles, three-quarter loadfor the second group of nozzles, and full load for a third group of nozzles where there are thr'ee; onozzles are disposed at different stages of groups,-all of which groups the turbine. Each successive groupof regu- -lation nozzles admits the steam required for the increased load and such additional steam -Joins the main flow of steam in the next `following rotating Wheel to work in the remain-` ing part of the turbine, Vand preferably each successive group of load regulation nozzles is carried by a stationary disc radially outside of and in juxtapositionl to the main guide canals thereof whereby the full ad-A mission added steam is introduced in a direction substantially parallel to the main flow and in a manner to join the same in the next rotating Wheel without any sub stantial disturbance of the flow and Working thereof. Throttling may take place in certain cases and under certa-in conditions at the intermediate regulating groups'of nozzles, but such throttling only applies to a4 part of the total quantity of steam consumed, with the resultant diminution of the throttlinglosses. The regulation, therefore, of the turbine is-mainly effected through the successive full admission controls of the main regulating nozzle groups disposed at different stages of the turbine, but if desired a finer and more exact regulation may be effected by dividing the full admissionl noz, r

zles into sub-groups which may be successively controlled to securemthe liner adJustments. Similarly the first mission nozzles may be divided into subgroups for still smaller loads, but ordinarily it is contempla-ted 'that the rst group of nozf zles as well as the subsequent groups will operate at full admission Whenever possible group of full adto avoid the losses due to partiall admission regulation, particularly when the admission pressureA is arclatively high one.

For a better'understanding of the invention, reference may be had to the accompanying cally illustrating the essentials of the invention, wherein: f

F ig. .1 contains graphs indicating the large control losses yat high pressures;

Fig. 2 is n tional view through a turbine embodying the invention;

Fig. 3 is a diagrammatic sectional view through the front end of the turbine along the line III-III in'Fig. 1, and Figs. 4 and 5 are diagrammatic sectional views adjacent subsequent groups of full admission nozzles along the lines V-V and IV-IV in Fig. 1.

drawings more or less diagrammatiadiagrammatic longitudinal sec- Referring to Fig. 1 the curves a and a illustrate steam consum tion alteration curves per-unit of output or aturbine operatfing at partial loads with throttleregulation and the curves b and b are similar curves for nozzle regulation at thirteen and thirty-five atmospheres pressure respectively. These curves show that nozzle regulation is more eilicient than throttle control, but both kinds of regulation become very ineiiicient wit-h decreasing loads below f ull load (ll/ 4), each of these curves showing increasing steam consumptions which are more pronounced as the load decreases,-the ordinates representing increasing steam' consumption with load reduction and the abscissae repre-i senting percentages of full load. I i

Referring to Figs. 2-5 I have indicated a multistage turbine having the stationary discs 27 which carry the rings of guide nozzles and the alternating rotor discs which carry the rings of rotating buckets 26. 'The turbine is provided with a full admission chamber 30 at theb first stage which is divided into tli-ree sections with intakes 9-10-11 leading (thereto. Working throughout the turbine is accomplished through the admission of steam by these intakes 9, 10 and 11, the steam' thus ad- 26 of the turbine. The turbine is so constructed and proportioned that with the intakes 9 10-11 fully open with no additional supply of steam at any other stage` in the turbine, it is capable of only working at partial load. For assuming larger loads, the turbine is adaptedto receive with full admission additional steam at intermei diate or lower pressure stages, as for example at the `tull admission chambers 3l and 32 each of which is divided into four sections with l intakes leading thereto and indicated respectivelye at 5*(i-7-8 and 1-23`-4s The chambers 31 andV 32 lead respectively to the auxiliary radially and putwardly disposed rings of guide canals or nozzles c and d. The construction is such .that the additional steam thus capable `of being admitted through the intakes 5-8 inclusive to the full adm'issioned nozzles c is just suticient to take care of a definite part of the load, this additional steam being introduced in a direction substantialparallel .to the main flow arid combinjig with the steam admitted intakes. 9-10-11 and working-co-joiiitly therewith throughout the remainder of the turbine. Similarly, for taking care of another definite part of the load, a set or roup of intakes 1-2-3-4 is disposed a out` the turbine casing at va lower pressure stageand leads into auxiliary stationary full admission (guide nozzles (l radially outwardly Vdisv pose with reference to the main stationary (l5 guide nozzles (l2) of that particular stage.

mitted .performing work on all the wheelstake place v itlages, would apply only to a part of the l'losses incident 'partial admission such as ventilation, Wind- The nozzle group d is adapted to'receive and admit a sutlicient quantity of steam to assume its definite proportion of the increased load. The turbine exhaust is indicated at 25. -Forvfull or maximum load live steam is admitted through all of the steam admissions l-ll inclusive or to the three separate groups of intakes admitting steam all the way around the turbine periphery. It the output or load should decrease to, say, approximately three-quarter load, the steam admissions 1-4 inclusive are shut oli? so that the turbine only receives fluid through the openings 5-11 inclusive, but all the way around` its periphery at both'points of admission. Similarly at, say, one-half load the connections 5 8 are shut off or closed and the turbine works as a full admission turbine with the working fluid passing only through the entrance openings 9-11 inclusive to the first stage. It is obvious, therefore, that with this arrangement the turbine works with full admission at the three definite percentage load values, as for example at one-half load, three-quarter and full load. Only three such full admission groups of nozzles are shown in the drawings, but additional full admission groups may be provided if desired. The preferred order of closing and opening the three fulladmission groups of intakes is that described above, but it may be expedient in certain cases to var this order, as for example by ppening tliie intakes 5 8 before opening the intakes 9-11, etc.v The main partial load values selected for any turbine unit depend upon the conditions of the particular plant. For example, main partial loads other than one-half and three- Aquarter loads maybe required to meet plant conditions, the mam purpose being to operate the turbine at all of such main partial loads at full admission in all stages, and with a minimum of pressure reduction control. By my invention I secure the -advantage that for loads below full load such as halfload or three-quarter load or other degrees may be found desirable in a given case, a full admissioned live'steam Supply is utilized asin the case of full load, and the throttling of the steam, which may at the intermediate ref gulatingy total steam supply, thereby reducing the to total throttle control and age, scavenging and eddy losses and those due to the varying back pressures at the intermediate Wheels and to unfavorable variations in steam velocitiesvin size and direction, and the" losses due to the decreased available heat drops occasioned by pressure reduction control. With this construction'l therefore the best thermo-dynamic efficiency practicallyl obtainable is approximated at' all the main plartial load values, for example, at onealf, three-quarter and 4/4 load. Theoretically, the best thermal etticienc is obtained when there are always and succeeding stages, but these departures are relatively small and in most cases apply only to a fractional part of the steam "sup- 'ply so that the losses in eiiciency caused by such variations in velocity arevery small as compared with the increased eiliciency obtained over other known turbine constructions for changing the steam supply with load conditions, vsuch as the straight throttle or nozzle control constructions. A further advantage obtained by my invention consists in that the power of the turbine may be y more finely regulated between the various main percentage load values such as onehalt` load, threequarter loadv and full load by em loying partial admission for regulation etween these main load values, but the losses dueto such partial admission occur only at the intermediate stage and apply only to a small part of the total steam supply. i

The adjustments between these definite percentage load valuesA might be effected by throttling the steam, but since the nozzle regulation, as shown in Fig. v1, is more efficient than the throttleregulation, the latter control is preferred, as by sub-dividing the main nozzle groups c and d of the additional guide blades so that if necessary only a portion of each main Group may be opened or closed, as is desire vFor example the nozzle group represented by d may be subdivided -into sub-groups 14-17 inclusive while the main nozzle group c inclusive may be sub-'divided into sub-groups 18-'21 inelusive. It is thereby possible to successive- Vly open or close the sub-groups 14-17 or -18-21 forf intermediate loads between the main load regulation` values. Such regulation for loads intermediate the main regulation values is thereby eected by the more etlicient nozzle regulation, and may be effected at the lower pressure-stages supplied with the additional working steam. For example, thesub-groups 14?-17 may be first successively controlled for such regulation before the successive conprol of the sub-groups 18-21.

In Fig. 3 I have indicated the first-nozzle group supplied by intakes 9*-10-1'1 as subdivided into nozzle groups 22, 23 and 24- which render it possible to'eilectregulation for load values below the main percentage values, as for example below one-half load, but ordinarily with turbines in practical installations seldom operating at below onehalf loads, these sub-divisions of the nozzle` group ywould not be .desired or necessary. Also with this arrangement it would be possible, of course, to regulate for varying load values by cutting in andout the groups 22, 23 and 24 while the other main groups 1-4 and 5-58 are fully open.

12 and 13 signify the rings of main guide nozzles for the main driving iuid flow working in the turbine and situated radially within the nozzles c and d respectively.

I have omitted from the drawings, for

.convenience in illustration, the regulating or controlling means for regulating the supply of working fluid to the intakes 1-11 inclusive, but it is understood that any suitable known regulating devices or system may be employed. The intakes 1 4, 5 8 and 9-1'1 are supplied with live steam of the same pressure and the pressure thereof may be reduced at the inlets 1-4 or at the intake nozzles of the intermediate intake stages or at both to function to greatest advantage with the main uid flow and expansion.

What I claim is:

1. A turbine of the elastic lui'd type inv cluding a plurality of alternating stationary discs "and lrotating wheels having alined rings of stationary nozzles and rotating canals for continuous uninterrupted flow and expansion of the steam fromv one ring to the other throughout the turbine, the high pressure end of the turbine including a ring of stationary nozzles and being provided with a steam supply means leading thereto, an intermediate stationary disc carrying also a. second and concentric ring of nozzles arranged immediately radially outside of and in close proximity to the main ring of nozzles carried by said intermediate disc and adaptedto direct steam intothe immediately following ring of rotating canals in substan-l tially parallel relation with the flow of steam working through the preceding nozzles and a separate steam supply means leading to said concentric ring of stationary nozzles 2. A turbine of the' character set forth in claim 1, wherein one of said steam supply means includes two or more separate steam supply chambers with separate inlets thereto.

cluding a plurality .of alternating stationary discs and rotating wheels having alined rings ,of stationary nozzles and rotating cafnals for the continuous uninterrupted flow and expansion of the steam from onaring to the other throughout the turbine, a ring ofV stationary nozzles leading to the first rotatlll() iso A turbine the. ensue fluid typekin.

vinandcoilliilllfg;

centric rings of stationary nozzles disposed at certain intermediate stages of the turbine and also carried by the stationary discs, each of said concentric rin s being arranged immediately radially outside of and in close proximity to the ring of nozzles carried by the stationary disc at that stage an'd adapted to direct steam into the immediately following ring of rotating canals in parallel relation Ito the flow of steam working through the preceding nozzles and a separate steam supply means for eachiof said con, centric rings of stationary nozzles.v

4. A turbine of the elastic fluid type including a plurality of alternating stationary discs and rotating wheels having alined rings of stationary nozzles and rotating canals for continuous and uninterrupted flow and expansion of the steam from one ring to the other throughout the turbines, the

high pressure end of 'the turbine being provided with a steam supply means for the first ring of stationary nozzles and the nozzles of the high pressure end of the turbine being adapted with full supply thereto to receive only a sucient quantity of steam for partial load on the turbine, an intermediate stationary disc carrying a concentric ring Y of stationary nozzles arranged immediately radially outside of and in close proximity to the stationary ring of nozzles carried by it,

' said concentric ring of stationary nozzles being adapted with full supply `thereto to receive a quantity of steam corresponding to a Y further part load value on the turbine and to direct it 'into the immediately following ring of rotating canals in parallel relation with rthe flow of steamworking inthe preceding alined nozzles, and a steam supply means for said concentric ring of stationary nozzles.

5. A high pressure steam turbine having 'a plurality of rings of stationary nozzles alternating with correspondinorings of rotating canals which are aline'd therewith for the continuous uninterrupted liowand expansion of steam from one ring to the other throughout the turbine, said rings of nozzles and rotating canals being divided into two or more groups, each of which groups gradually increases in exit area toward the low pressure end thereof, but each succeeding group of nozzles and canals having an abrupt increase in area as compared with that of theV immediately preceding group; a steam supplymeans leading to the first group, and a separate steam supply, 'means for each succeeding group leading to thefirst rotating ring thereof to supply an'adflitional quantity! of steam 'corresponding to the abrupt increase in area thereof and adapted to direct the additional steam 4into the rotating ring in a.' directio'n parallel to the flow of the main body of steam working the preceding (group.

6. A high pressure .steam turbine having a plurality of alined alternating rings of stationary nozzles and rotating canals with a steam supply means and ringot stationary .area toward the low pressure end' thereof,

the lirst group being of a construction and capable of receiving only a suflicient quantity of steam to operate the turbine at a definite partial load value,'and ea'ch succeeding group of nozzles and canals having a larger area and 'adapted to receive an additional quantity ofsteam corresponding to the increase in area and to a denite percentage load value of the turbine a regulating ring of tationary nozzles leading to each interme- 1ate andin juxtaposition to the lastring of the adjacent preceding group,v and a separate Aauxiliarysteam supply means communicating with each ofsaid regulating rings.

. 7. A multistage turbine of the elastic fluid type including a plurality of alternatf ing stationary discs and rotating wheels havrotating canals for continuous and uninter rupted working and expansion of the steam from one ring to the other throughout the turbine, the lirst stage including a ring of stationary nozzles capable with full supply thereto of operatingthe turbine at a definite chamber throughout the tur- .group and disposed radially outside of ing a'lined rings of stationary nozzles and partial load value, each of two intermediate stages of said turbine including two separ ate concentric rings of stationary nozzles, the outer of 'said .stationary concentric rings of nozzles having separate steam sup ly means and each ofthem capable with liiill supply thereto of operating the turbine at a denite partial load value.

8. A turbine'o the character set forth in claim 7 wherein one of'the separate steam supply means and corresponding outer concentric ring. of stationary nozzles at' an'in termediate stage is divided into separate sections for regulation for load values be Ltweenthe deinite partial load values.

9; A multistage high pressure turbine of the elastic fluid type having an admission ring of stationary nozzles at its high pressure end, but capable of only partial load operation when fully supplied by steam thereby, and having at least one stage providedfwith an auxiliary ring of .stationary nozzles for vthe reception of addiintermediate tionalV working fluidto-.tak'e care of a larger l load,- the admission nozzles for said intermediate stage being divided into Vups disposed in separate and distinct'chambers with' Y Separate intake# therein@ whereby regulation for loads intermediate the partial load and the larger load values may be ev A fected.

l0. A multistage high pressure elastic fluid turbine having a single stationary guide nozzle ring for full supply at the first stage and for-supplying full pressure live fluid to the turbine, additional load varying admissions for live fluid separate from and disposed at intermediate stages of dierent pressures, said additional admissions including two or more separate full supply guide nozzle rings which are radially outwardly disposed with respect to the corresponding mainv guide nozzle rings and are adapted to be successively controlled for regulation for varying loads and the admission of steam into the main working nozzles in parallel If'lelation to the flow of the main working uid. i

11. A multistage high pressure elastic fluid turbine having/an admission ring of stationary nozzles at its high pressure end and capable of only partial load operation with lhigh pressure fluid fully admitted thereinto and working throughout the turbine separate load varying admission chambers at intermediate stages with substantially full admission about the whole circumferenoes of the intermediate stages for regulating the admission of liye fluid thereinto for successively larger loads and rings of admission nozzles in communication with said chambers and leading directly into the buckets of rotating wheels.

` 12. A. steam turbine of the multistage type having a plurality'of alternating rings of stationary nozzles and rotating canals for the continuous working and expansion of' the steam from one ring to the next, the first stationary ring of nozzles at the high pressure .end of .the turbine being capable of supplying only a sufficient quantity of steamrto `operate the turbine at partial load value, a steam supply means leading thereto, an auxiliary ring of stationary nozzles disposed at a stage of substantially lower pressurethan the iirst stage and adapted .to introduce directly into a rotating ring of nozzles at full supply a quantity of steam corresponding to a further partial load value of the turbine, and a steam supply means communicating with said auxiliary ring of stationary nozzles.

In testimony whereof I aiiix my signature.

FRANZ LSEL. 

